Emerging therapeutic options for the management of hepatitis C infection

Quality of life in Brazilian patients with treated or untreated chronic hepatitis C

Introduction:

Multiple factors negatively affect the quality of life of patients infected with hepatitis C virus. This study aims to evaluate the effect of pharmacological treatment on the quality of life of these individuals.

Methods:

This is a cross-sectional study conducted in two Southern Brazilian centers that used two instruments (a generic and a specific one) for measuring the quality of life in patients with chronic hepatitis C: the Short Form-36 (SF-36); and the Chronic Liver Disease Questionnaire (CLDQ) for liver disease. We included patients from two centers without any treatment (control group), or receiving medication (peginterferon + ribavirin ± telaprevir or boceprevir, i.e., respectively, dual, and triple therapies).

Results:

One hundred and forty-seven patients were included. Patients under treatment (n = 86) had a lower score in 7 of the 8 SF-36 domains, with statistical significance (p<0.05) only for the emotional function domain. Patients who were not treated (n = 58) had higher scores in 4 of the 6 (p<0.05) CLDQ domains. A comparison of patients, receiving dual or triple therapies for both questionnaires, was only significant in the Vitality domain from CLDQ.

Conclusions:

Treatment can affect the subjective perception of patients regarding quality of life. Due to the complexity of the disease, each patient must be evaluated in multiple dimensions. Thus, the results may be useful for understanding the patient's perceptions during treatment, and it can also serve as a reference for care instructions.

Pharmacokinetics and Tolerability of Anti-Hepatitis C Virus Treatment with Ombitasvir, Paritaprevir, Ritonavir, with or Without Dasabuvir, in Subjects with Renal Impairment

BACKGROUND

The direct-acting antiviral agent (DAA) combination of ombitasvir and paritaprevir (administered with ritonavir) with (3D regimen) or without (2D regimen) dasabuvir has shown very high efficacy rates in the treatment of chronic hepatitis C virus (HCV) infection. Renal impairment, a common comorbidity in patients with chronic HCV infection, can influence the pharmacokinetics of antiviral agents and hence their efficacy and safety profiles.

OBJECTIVE

The aim of this study was to evaluate the influence of renal impairment on the pharmacokinetics and tolerability of the 3D and 2D regimens.

METHODS

Overall, 24 subjects, six in each of four renal function groups (normal, mild, moderate, and severe), received a single dose of the 3D and 2D regimens in separate dosing periods. Plasma and urine were analyzed to assess the effect of renal impairment on drug exposure.

RESULTS

DAA exposures changed by up to 21, 37, and 50 % in subjects with mild, moderate, and severe renal impairment, respectively, versus subjects with normal renal function. Ritonavir exposure increased with the degree of renal impairment (maximum 114 %). The half-lives of DAAs and ritonavir in subjects with renal impairment were generally comparable with those in healthy subjects. No safety or tolerability concerns arose in this study.

CONCLUSION

The 3D and 2D regimens do not require dose adjustment for patients with HCV infection and concomitant renal impairment.

Dose- and Formulation-Dependent Non-Linear Pharmacokinetic Model of Paritaprevir, a Protease Inhibitor for the Treatment of Hepatitis C Virus Infection: Combined Analysis from 12 Phase I Studies

BACKGROUND AND OBJECTIVES

Paritaprevir is a direct-acting antiviral agent that is a component of approved multidrug regimens used in the treatment of hepatitis C virus (HCV) infection. A population pharmacokinetic model for paritaprevir was developed using data from formulation, bioavailability, and drug-drug interaction studies that evaluated the pharmacokinetics of paritaprevir (coadministered with ritonavir to enhance exposure) with or without ombitasvir and/or dasabuvir at different paritaprevir dose levels.

METHODS

A non-linear mixed-effects modeling approach was applied to data from 12 phase I, single- and multiple-dose studies that enrolled a total of 369 healthy volunteers. Age, sex, race, ethnicity, body weight, body surface area, body mass index, and baseline creatinine clearance were evaluated as covariates during model development. In addition, the influences of dose, formulation, and concomitant medications (e.g. ombitasvir and dasabuvir) on paritaprevir bioavailability were included in the model.

RESULTS

A two-compartment model with first-order absorption and elimination optimally described paritaprevir plasma concentration-time data. Paritaprevir bioavailability was formulation- and dose-dependent, and increased supraproportionally. The accumulation of paritaprevir was 1.57-fold on repeated dosing compared with the first dose. Coadministration of dasabuvir increased paritaprevir bioavailability by 59 %; however, ombitasvir coadministration did not affect the pharmacokinetic profile of paritaprevir. No subject-specific covariate influenced the paritaprevir pharmacokinetics. The pharmacokinetic model was robust in bootstrap evaluations and was consistent with observed data based on diagnostic goodness-of-fit plots and visual predictive checks.

CONCLUSION

The complex pharmacokinetics of paritaprevir were well described by the model, which can be used as a basis for clinical trial dosing and further evaluations in patients with HCV.

Population Pharmacokinetics of Paritaprevir, Ombitasvir, Dasabuvir, Ritonavir, and Ribavirin in Patients with Hepatitis C Virus Genotype 1 Infection: Combined Analysis from 9 Phase 1b/2 Studies

Direct-acting antiviral agents (DAAs) are established as the standard of care for chronic hepatitis C virus (HCV) infection. One of the newest additions to the HCV arsenal is an oral three-DAA combination therapy (i.e., the 3D regimen) that does not require concomitant use of pegylated interferon. The clinical development program for the 3D regimen has yielded a robust dataset that is inclusive of various dosing schemes and a diverse patient population. Using data from nine phase 1b/2a/2b studies that enrolled patients with HCV genotype 1 infection, population pharmacokinetic models were developed for each component of the 3D regimen (ombitasvir, paritaprevir, ritonavir, and dasabuvir) and for ribavirin, an adjunctive therapy used to enhance therapeutic efficacy in some populations. Formulation effects, accumulation, relative bioavailability, and interactions between DAAs were assessed during model development, and demographic and clinical covariates were identified and evaluated for their effects on drug exposures. Proposed models were assessed via goodness-of-fit plots, visual predictive checks, and bootstrap evaluations. Population pharmacokinetic models adequately described their respective plasma concentration-time data with precise and reliable model parameter estimates and with good predictive performance. Covariates, including age, sex, body weight, cytochrome P450 2C8 inhibitor use, non-Hispanic ethnicity, and creatinine clearance, were associated with apparent clearance and/or apparent volume parameters; however, the magnitude of effect on drug exposure was modest and not considered to be clinically significant. No patient-related or clinical parameters were identified that would necessitate dose adjustment of the 3D regimen in patients with HCV genotype 1 infection.

Delta hepatitis-related thyroid disease: a unique phenomenon

Introduction

Hepatitis delta virus (HDV) infection is a serious health problem worldwide. Thyroid disturbances represent a major limitation to the efficacy of interferon treatment targeting chronic HDV (C-HDV) infection. Moreover, pre-treatment thyroid diseases may be influenced by interferon therapy. Despite this, the characteristic features of the thyroid diseases in C-HDV patients remain poorly characterised.

Aim

To determine the prevalence of thyroid diseases and evaluate the impact of delta hepatitis on thyroid function tests.

Material and methods

We retrospectively reviewed the charts of 127 hepatitis C virus (HCV)-negative adults, treatment-naive outpatients with C-HDV, between July 2013 and July 2014. Thyroid-stimulating hormone (TSH) and thyroid antibodies (TAbs) including anti-thyroid peroxidase antibodies (anti-TPO), liver transaminases, and other routine laboratory tests were conducted during the study period.

Results

A total of 127 C-HDV patients (female 52.9%, mean age 54.5 ±8.01 years) were enrolled. The rate of hypothyroidism, defined as a TSH level above 10 IU/l, was 4.7%. No patient had hyperthyroidism. Both elevated levels of liver transaminases and HDV ribonucleic acid (HDV-RNA) were positively correlated with high levels of thyroid autoantibodies.

Conclusions

The rate of hypothyroidism is higher than the rate of hyperthyroidism at baseline. Most remarkably, for the first time we discovered a correlation between disturbed thyroid autoantibodies and elevated liver transaminases as well as high HDV-RNA levels even in euthyroid delta hepatitis patients. But in order to have an adequate understanding of such correlations, further studies are needed.

Effect of Treatment for CHC on Liver Disease Progression and Hepatocellular Carcinoma Development in African Americans

BACKGROUND AND AIMS

African Americans (AA) historically have a low response rate to hepatitis C therapies, and there is limited information available for this patient population regarding the development and treatment of chronic hepatitis C (CHC). The aim of this study was to evaluate liver disease progression and hepatocellular carcinoma (HCC) development in AA with CHC.

METHODS

Between 1995 and 2008, 246 AA patients with CHC were identified from a database of patients and followed until 2012-2013 (average 8 years) or the development of HCC after 2008.

RESULTS

Viral clearance (intent to treat; sustained virus response (SVR)) was achieved in 15% of patients with interferon based therapies with or without ribavirin. AA patients who achieved an SVR (n=22) did not develop HCC or new onset cirrhosis, whereas the HCC incidence in untreated AA patients was 23% (51/203). Patients who achieved an SVR also had improved fibrosis, as defined by the AST Platelet Ratio Index (APRI) and Fibrosis-4 (FIB-4) score, relative to nonresponders and untreated patients.

CONCLUSIONS

The severity of liver disease at the first visit (except for cirrhosis) correlated with the development of HCC, but because of the overlap in values between patients, these measurements were not useful for predicting individual risk. Since cirrhosis at the first visit was not a predictive factor, treatment with newer antiviral therapies is the best option for reducing the incidence of advanced liver disease and its harmful outcomes in the AA population.

Health care-associated hepatitis C virus infection

Hepatitis C virus (HCV) is a blood-borne pathogen that has a worldwide distribution and infects millions of people. Care-associated HCV infections represented a huge part of hepatitis C burden in the past via contaminated blood and unsafe injections and continue to be a serious problem of public health. The present review proposes a panorama of health care-associated HCV infections via the three mode of contamination that have been identified: (1) infected patient to non-infected patient; (2) infected patient to non-infected health care worker (HCW); and (3) infected HCW to non infected patient. For each condition, the circumstances of contamination are described together with the means to prevent them. As a whole, the more important risk is represented by unsafe practices regarding injections, notably with the improper use of multidose vials used for multiple patients. The questions of occupational exposures and infected HCWs are also discussed. In terms of prevention and surveillance, the main arm for combating care-associated HCV infections is the implementation of standard precautions in all the fields of cares, with training programs and audits to verify their good application. HCWs must be sensitized to the risk of blood-borne pathogens, notably by the use of safety devices for injections and good hygiene practices in the operating theatre and in all the invasive procedures. The providers performing exposed-prone procedures must monitor their HCV serology regularly in order to detect early any primary infection and to treat it without delay. With the need to stay vigilant because HCV infection is often a hidden risk, it can be hoped that the number of people infected by HCV via health care will decrease very significantly in the next years.